Let's talk Japanese infantry tactics...

So they inspired that dude who is now unemployed?

Without a bubble, how does one aim it? There's no plumb bob on it.

 

It was held at roughly a 45 degree angle, later production was fitted with a bubble level, but early production just used the Mark 1 eyeball. A knob adjusted the length of the barrel for range(and was so marked - 10 inches depth for about 650 meters range). A groove was usually marked on the barrel to serve as an iron sight.

 

And since it was intended as a lightweight short range mortar, it wasn't hard to get hits even with the Mk 1 eyeball. Most often it was used at under 300m range, and it's not hard to walk them in at such ranges. Mortars are scary.

 

Yes, maybe the shape of the base-plate was responsible for that belief. The Japanese had also another light mortar, the Type 98 (50 mm), which had a more conventional layout.

These weapons should have been useful to suppress enemy machine guns, but I wonder if the jungle vegetation hampered their use. Would such light shells be deflected by tree branches etc?

 

Thanks. Where I worked there was one with no bubble on it.

 

Probably, if the branch was big enough. On the other hand, the shells had timed fuses instead of impact ones, so that they would not detonate in overhead branches.

 

....

..I was in mortars.....allow me to say again what my uncle told me...he did not say much at all about the war --but one of the very few things he did say was, that the Germans were ''accurate with their mortars''''' = very telling he would speak about mortars and not much else!

....direct fire with sight, bipods and a good gunner, is very, very accurate ....our gunners would put rounds on an '''anthill''' in 3 rounds with direct fire [ when you can see the target with the mortar sight ] ....our gunners did just that one time--on an anthill or something, not very big
....of course indirect fire is not as accurate.....and it depends on how the mortars are set in [ I forget the exact term ].....we had one of those engineering type bipod mounted scopes that could ''accurately'' set up the mortars not only singly -but also as a unit [ all set up '''roughly''' in the '''same''' direction]
....the other less accurate way was to just use a compass behind the mortar for setting them up--- aiming in the same general direction= someone would stand behind the mortar and tell the gunner to move the barrel this way or that = after that, the FDC would give the '''''directions''
..the other thing is setting up the aiming stakes for indirect fire = stakes were set up by each mortar = would be variances.

...if fire was needed right away, and you are on the ''move'', you could not set up indirect fire ''accurately''
...I would say direct fire from the '''knee'' mortars would be more accurate/ fairly accurate at close ''range''' as you say
...and it depends on how much ranging ammo you have
...also, depends on how much training/experience the gunner has

...I was with 81mm mortars ...but the rifle companies had 60mm with triggers --that could be used liked the knee mortars ...I think I used them....probably in ITS [ Infantry Training School ]...been about 30 years ago, so my memory is not so good

 

...base plate stability is very, very important--especially with heavy mortars ...with our 81s, on the first round, the base plate could move ''a lot'' = the round will be ''far away'' from the desired location ..so optimally, for heavy mortars, you want to fire a ''few'' rounds to gt the base plate 'seated''
--yes, it does have an interesting base plate

 

..my questions then would be:
1. how much and how many times did they have the opportunity to attack a a weak position? I would think US positions would be more or less ''strong''' all around...it would be militarily wrong to not do that
--each company/etc would have their heavy weapons ..etc
2. how much time did they have to recon? with the Canal, terrible terrain --especially for night attacks --except a few places
--example: Tenaru Battle = easy going up the coast...not many other places to attack and not get disorganized/etc
--example: for the Battle of the Ridge, they were behind schedule as it was

 

Yes...However US artillery, in the ETO, was not firing up through a jungle canopy to hit their targets either

 

Ask any sniper what they fear and they'll tell you; a well trained mortar team. Yeah, I have seen US mortar crews and they're scary...like, REALLY scary.

 

..yes, I had a thread discussing forest/etc terrain and arty/mortars/firing/impact area/FO problems/etc
..even for the ''knee mortar'', you need a fairly clear area to fire from and to adjust fire

..I was just watching a great video on the ''knee mortar'''....it said you could adjust range down to 55 meters. I think.....
..yes, another consideration I was thinking about= where can they fire from--safely?

 

Forgotten Weapons?

There were two range scales, the8 onev on the left side is for the Type 89 round, which was purpose-made for such weapons. That scale goes from 120 to 650 meters. The one on the right side is for use with a Type 91 multi-purpose (hand/rifle/mortar) grenade with a booster attached, and goes from 40 to 190 meters.

Safely? From behind cover, 610 meters would still be in rifle and machine gun range. Even at 40 meters, you would have to be very very unlucky to catch a piece of shrapnel from your own round.

 

Yeah, it pinch hits for a rifle grenade with a larger payload. While it was far from a perfect weapon, it was a very handy mortar. The light weight and ease of carry made it especially useful in the jungle. In triple canopy, no mortar is really useful in WW2, but give it just the smallest clearing and that mortar can do some evil work. As a soldier, I feared mortars FAR more than enemy rifle or machinegun fire.

 

yes.. they have a lot of good stuff IMO.....yes, the mortar is much more complex than what meets the eye